Automatic warning-signal for air-brake systems.



No. 869,323. PATENTED OCT. 29- 1907.

' R. P. NOLAN.

AUTOMATIC WARNING SIGNAL FOR AIR BRAKE SYSTEMS.

APPLIOATION FILED NOV. 7, I906.

n'qvmt'rom wrmns fl v R.P.NOLA N.

I UNITED STATES PATENT OFFICE.

AUTOMATIC WARNING SIGNAL FOR Alli-BRAKE SYSTEMS.

Specification of Letters Patent.

PatentedOct. 29, 1907..

' Applicatio fil ed November 7, 190 6- Serial No. 34:2.431l

I To all whom it may concern:

Be it known that I, RICHARD PETER NOLAN, of Havelock, in the county ofPeterborough, Province of On-- tario, Canada, have invented certain newand useful Improvements in Automatic Warning-Signals for Air- BrakeSystems, of which the following is a specification. My invention relatesto improvements in signal de- .valve, the details of the device-beingmore fully set forth and described in the accompanying specificationsand drawings Figure 1- is a sectional view through the valve whenclosed. Fig. 2 is a sectional view when open. Fig.3

V responding parts in each'figure.

Of late many accidents have occurred owing to the.

is an elevation showing the complete device with the signal attachedthereto.

In the-drawings like letters of reference indicate corfailure of the airbrakes to operate in the various cars when simultaneously applied by theengineer. This has been due in some cases to the air gradually escapingand lowering the pressure to such an extent that the brakes will notoperate. the pressure is suddenly lowered the air brakes will beautomatically applied but very frequently a gradual lowering could takeplace without any effect being "produce'd on the brakes. A further causeof accident is the angle cock placed at each end of each car whichfrequently by jarring becomes'closed and so cuts off thatv car from therest of the system. -.The airin this car may then be gradually reducedin pressure without any ef-- fect being noticed in the other cars.Sometimes a gage is attached tojeach car but it isevident that this isan unreliableinletlied of indicating the; condition of so vital a matterasthe air brake system and might easily be overlooked by the train crew.In my invention whenever-f the pressure falls below-a. given amount aloud warning signal is at once produced which will attract the attentionof the train crew to the leakage. 4

Referring to the drawings A .is the valve the details of which may bevaried the essential features being the movable valve disk a which isnormally pressed'away Of course as is well known if shown the valve diskis cylindrical provided with a conical lower face and has a stem 2secured thereto, the opposite end of which extendsfinto a slot providedin a nut g screwed in an aperture h in the lower side of the valvehousing. Access is gained to the top of the valve disk through thehousing by means of a holei' normally closed by a cap nut j screwedtherein.' The upward movement of the valve is regulated and limited bymeans of a set-screw k extending through the cap nut and adapted to'abutthe top of the stem e when the valve is in its uppermost position thestem 6 being extended beyond the upper side of the valve disk for thispurpose. One side of the valve housing is connected by asuitable pipe Ito one of the conducting'pipes m of the air brake system andthe'opposite side'is connected by a similar pipe n to a suitablesignaling device B which asshown is an air whistle, 'This however, may

be any form of signaling device which can be operated by the passage ofairtherethrough.'

In carrying out my invention one ofthe valves will i be attached to theair brake pipes in each car. Under normal conditions the pressure of theair in the air brake pipe exerted on the top of the valve disk a willhold the same tightly against its seat b and prevent any passage of airthrough the valve. As soon however, as the pressure falls below apredetermined amount the compression spring e will lift the valve offits seat and permit theair to escape through the valve to the signalingdevice B operating the same to produce a loud that it will operate thevalve when the pressure is lowered a predetermined extent and'yet havesuflicient pressure to operate the brakes satisfactorily. Adjustment isprovided for the tension in this spring by means of the nut 9 .wherebyit the spring weakens in strength the'weakness may be made-up for by agreater compression. I

It will be observed that no matter how gradually the pressure lowers yetthe valve will be lifted off its seat immediately on the pressurepassing below the given point and I have found by testing that thisvalve will i i be opened and closed by a difference inpressure notexceeding one half pound per square inch. The pressure at which it wouldgenerally be desirable to have the valve operate would be fifty poundsper square inch but this obviously might be changed to suit differentcircumstances. v

It will be readily understood that while I have described with greatparticularity of detail one specific .warning signal. The strength ofthe spring 0 is such embodiment of my invention certain changes might bemade therein within the scope of the appended claim ithout departingfrom the spirit of my invention.

What I claim as my invention is In an automatic warning signal for airbrake systems, the'combination with the globe valve housing andsubstantially horizontal valve seat therein of a valve operating on 10of the housing having a recess therein into whichthe through the top ofthe valve housing, a set screw extending through the same and adapted tolimit the upward movement of the valve by engaging the stem thereof.

' Signed at Havelock, in the Province of Ontario,' this 29th day ofOctober, 1906.

RICHARD PETER NOLAN. Witnesses:

'lnos. Bnxxn'r'r, S'rnrHnN BERNARD O'HARA.

